Touch Screen becomes unresponsive when receiving call

Has anyone else had problems with their touch screen becoming unresponsive when a call is received? It started happening to me a few days ago and again today for a total of two times. I tried restarting the phone after the first time, but that didn't help apparently. The touch screen stays unresponsive even after the call goes to voicemail, and double tapping will not wake it up. Hitting the sleep button once or twice is the only thing that returns the touch screen to normal. Since it works normally otherwise, this leads me to believe that it is a software issue rather than a hardware defect. Does anyone know of any software that would interfere with receiving calls or the touch screen's functioning?